CSG said the deal strengthens its position in the property maintenance sector, while benefiting from the acquired company's expertise in end-of-term lets.
Dyce-based CSG has retained all seven staff employed by PM further to the deal, including company founder Pauline Matthews. Ms Matthews has been appointed to the new post of operations manager of CSG's property maintenance division.
CSG, which currently employs 370 staff, expects to add a further 30 to its headcount in the next three months.
The PM deal is its sixth acquisition in three years, having recently launched a division in Tayside and Fife and appointed Jocky Scott, the former manager of Dundee Football Club, as its branch manager.
It remains on the look-out for acquisitions in the central belt and possibly further afield.
Calum Johnston, commercial director at CSG, said: "We are delighted to welcome Pauline and the rest of the team under the CSG banner. The acquisition is a good fit and ties in well with our existing portfolio.
"We hope this move will further boost our presence in the residential sector and complement the hard work previously put in by our own staff as we continue to grow the business."
CSG, which maintains more than 300 contracts in Aberdeen, Aberdeenshire, Dundee, Fife, Inverness and the Northern Isles, recently moved to new premises in Wellheads Industrial Centre. The 7500 square foot site is three times larger than its former home in Airside Business Park.